The present invention relates to a liquid crystal device, a method of manufacturing the liquid crystal device, and an electronic apparatus, and more specifically, to the structure of a liquid crystal device having an alignment film for aligning liquid crystal, and a method of manufacturing the liquid crystal device.
Generally, a liquid crystal device has a cell structure in which liquid crystal is enclosed between a pair of substrates, and an alignment film which regulates an initial aligned state of liquid crystal is formed in the inner surface of each substrate. As a method of forming an alignment film, the alignment film is formed, for example, by coating uncured resin, such as polyimide, on the inner surface of a substrate by a spin coating method, a printing method, etc., and performing drying or baking, etc.
Meanwhile, according to the type of display of liquid crystal devices, there are a transmissive liquid crystal device which causes illuminating light, such as back light, to be transmitted, thereby performing display, and a reflective liquid crystal device which causes outdoor daylight, etc. to be reflected, thereby performing display with reflected light. In particular, a transflective liquid crystal device which enables both the transmissive display and reflective display is often mounted in portable electronic apparatuses. This transflective liquid crystal device has the structure in which pixels each having a light-transmitting region which enables the transmissive display with the back light, and a light-reflecting region which enables the reflective display with outdoor daylight are arranged within an effective driving region.
In the above transflective liquid crystal device, the reflected light which constitutes the reflective display passes through a liquid crystal layer just one time, whereas the transmitted light which constitutes the transmissive display passes through the liquid crystal layer reciprocally two times. Therefore, the degrees (retardation) of light modulation of the liquid crystal layer to the display lights will differ greatly in the transmissive display and reflective display. For this reason, in order to reduce a difference in the light modulation in the transmissive display and reflective display, the thickness of the liquid crystal layer in a light-reflecting region is generally made smaller than the thickness of the liquid crystal layer in a light-transmitting region.
Specifically, the thickness of the liquid crystal layer is controlled by partially forming a transparent insulating film on the inner surface of a substrate. That is, the transparent insulating film is formed in the light-reflecting region of a pixel, and the transparent insulating film is not formed in the light-transmitting region so that the thickness of the liquid crystal layer sandwiched between a pair of substrates may differ in the light-reflecting region and the light-transmitting region.
However, the above transflective liquid crystal device has problems in that, since the transparent insulating film is partially formed on the substrate, when an uncured alignment resin is coated on the substrate, the alignment resin is accumulated in a non-formation region (light-transmitting region) of the transparent insulating film, and this invites any thickness unevenness of the alignment film, which deteriorates display quality. Thus, a technique of continuously forming a concave light-transmitting region between adjacent pixels to increase the flowability of alignment resin, thereby reducing any thickness unevenness of the alignment resin, is proposed (for example, refer to JP-A No. 2004-325822 (particularly, FIGS. 3, 13, or 17).
However, with the above-mentioned liquid crystal device, since the concave light-transmitting region continues between pixels, the thickness unevenness of the alignment resin in the light-transmitting region is not sufficiently solved sometimes, though the flowability of the alignment resin improves. For example, in a case in which a transparent insulating film is formed in such a pattern that a light-reflecting region is continuous between pixels, a continuous light-reflecting region is interposed between continuous light-transmitting regions. Thus the thickness of the alignment resin which has flowed into the region from the light-reflecting region may vary in a direction in which the light-transmitting regions continue. In particular, any thickness unevenness of the alignment resin may occur at the peripheral edges of the light-transmitting regions near the light-reflecting region, which deteriorates display quality. Further, in a case in which alignment resin is coated by a printing method, any deterioration of display quality is sometimes inevitable depending on the relationship between a print direction and a continuation direction of light-transmitting regions.
Meanwhile, an example in which a light-reflecting region in the shape of an island is formed in every pixel is also disclosed in the above-mentioned liquid crystal device. In this case, since a grooved recess is formed also between light-reflecting regions of each pixel, it is considered that alignment resin can flow in all directions, and consequently any thickness unevenness of the alignment resin is reduced. However, in this case, since the distance of the peripheral edge becomes large compared with the area of the light-reflecting region, there is a problem in that any poor alignment of liquid crystal is apt to occur due to a level difference generated at the peripheral edge of the light-reflecting region, and consequently the display quality gets worse.